A menu group is one complete navigation set. The All Menu Groups table lists each group with its Menu (#id and title), Position (Header or Footer), an Active toggle and a delete Action. Only one group per position can be active at a time - the active header group renders in the site header and the active footer group in the footer. You can keep several inactive groups (seasonal, campaign) and switch with the toggle, or assign a group to particular pages with Show on pages inside the builder.